Hannan EL et al. (2007) Off-pump versus on-pump coronary artery bypass graft surgery: differences in short-term outcomes and in long-term mortality and need for subsequent revascularization. Circulation 116: 1145–1152

The proportion of CABG surgery that is performed off-pump has increased in recent years, yet there are no definitive data comparing the outcomes of this procedure with those of conventional on-pump surgery.

In this large observational study, Hannan et al. used New York State registry data to compare the short-term and long-term outcomes of 35,941 patients who underwent on-pump CABG surgery with those of 13,889 patients who underwent off-pump CABG surgery (OPCABG). After adjustment for risk factors, patients who underwent OPCABG had lower inpatient or 30-day mortality (odds ratio [OR] 0.81, 95% CI 0.68–0.93), lower rates of perioperative stroke (OR 0.70, 95% CI 0.57–0.86) and respiratory failure (OR 0.80, 95% CI 0.68–0.93), and a higher rate of unplanned operations during the index admission period (OR 1.47, 95% CI 1.01–2.15) compared with patients who underwent on-pump CABG surgery.

At 3 years, risk-adjusted mortality did not differ between the OPCABG and on-pump cohorts (hazard ratio [HR] 1.01, 95% CI 0.92–1.10). Compared with patients who received on-pump surgery, however, those who underwent OPCABG had a significantly higher rate of subsequent revascularization after risk adjustment (HR 1.50, 95% CI 1.32–1.70) and after pairwise matching for predictors of type of surgery (10.1% vs 6.4%; HR 1.55, 95% CI 1.33–1.80).

The authors recommend that randomized controlled trials be conducted to compare OPCABG with on-pump CABG surgery, in order to determine which patient groups benefit most from each procedure.